Bangladesh has proposed joint military operations with Myanmar against Rohingya militants fighting in Rakhine state as the UN raised fears over reports of civilians killed during fresh violence in recent days.
An upsurge in fighting in Rakhine, an impoverished state neighbouring Bangladesh, has been raging since Friday when Rohingya militants staged coordinated ambushes against Myanmar's security forces.
More than 100 people, including about 80 militants, have been confirmed killed in the fightback, which has seen thousands of Rohingya villagers fleeing for Bangladesh.
The United Nation's Secretary-General Antonio Guterres "is deeply concerned at the reports of civilians being killed during security operations in Myanmar's Rakhine State", according to a statement from spokesman Stephane Dujarric.
He called on Bangladesh to step up assistance to civilians escaping the violence, noting "many of those fleeing are women and children, some of whom are wounded".
More than 3,000 Rohingya have arrived in Bangladesh from Myanmar, where the stateless Muslim minority faces persecution, in the past three days, the UN refugee agency said Monday.
Bangladesh has said there are thousands more Rohingya massed on its border with Myanmar, where it has stepped up patrols and pushed back hundreds of civilians who have tried to enter.
Among the refugees seeking shelter are women carrying young children and babies.
One Rohingya refugee, Laila Begum, revealed the extent of the violence and said she only found out about her family’s deaths from locals.
"I have not seen when my husband was killed. They [Myanmar military] took him away from our house and then killed him," she told Reuters.
"Villagers told me that my husband was killed. They killed my husband and my son-in-law."
Government officials have placed the death toll at 104 so far but Rohingya advocate groups told Al Jazeera it was much higher- saying the number of those killed is at least 800.
But the news service was unable to confirm this estimate.
One villager Aziz Khan said the military descended on his village in an early morning raid which took the lives of at least 11 people.
"When they arrived they started shooting at everything that moved. Some soldiers then carried out arson attacks," he told Al Jazeera.
"Women and children were also among the dead... Even a baby wasn't spared."
The refugees' flight comes as Human Rights Watch said it had satellite data "consistent with widespread burnings" in 10 populated areas of the violence-wracked wedge of Rakhine State near Bangladesh.
Those include Rohingya villages as well as Rakhine-majority settlements attacked by the militants.
In a meeting with Myanmar's charge d'affaires in Dhaka, a top Bangladeshi foreign ministry official proposed joint military efforts against the militants along the border.
"If Myanmar wished, the security forces of the two countries could conduct joint operations against the militants, any non-state actors or the Arakan Army along the Bangladesh-Myanmar border," a foreign ministry official said on condition of anonymity, as he was not permitted to speak to the media.
'We had no other options but to engage in a war'
The Arakan Rohingya Salvation Army (ARSA) is a militant group that says it is fighting to protect the Muslim minority from abuses by Myanmar security forces and the majority-Buddhist Rakhine community.
ARSA claimed responsibility for the attacks carried out on 25 police stations in the country’s west on Friday that triggered the latest spate of violence that ended the lives of 104 people.
The militant group’s commander-in-chief took to social media in a new video and dubbed the recent violence as ‘defensive war’ - saying it was in response to harassment from Myanmar military and blockades of Rohingya villages.
"We could no longer stand still in this state of affairs and have to save the lives and properties of Rohingya victims," the militant group's leader Abu Ammar Jununi said as he was flanked by two masked men with assault rifles.
"The Burmese brutal soldiers besieged and surrounded us in several places and thus we [had] no other options but to engage in a war."
Jununi called on international aid groups to stay and help, but the United Nations had taken steps to evacuate all non-essential staff for the region.
"The conspiracy by the Burmese brutal military regime and Rakhine extremist to expel international [non-government organisations] is designed and intended to starve the Rohingyas to death in the absences of these international bodies," he said.
There was no comment from the Myanmar diplomat.
At the weekend, as violence in Rakhine worsened, Bangladesh's foreign minister summoned Myanmar's charge'd affaires in Dhaka to express "serious concern" at the possibility of a fresh refugee influx.
There are already some 400,000 Rohingya refugees in Bangladesh in squalid camps near its border with Myanmar.
Bangladesh is waging a bloody crackdown on homegrown Islamist militancy and has vowed 'zero tolerance' towards violent extremism, domestic or otherwise, on its soil.
Dhaka has repeatedly asked Myanmar to take back the Rohingya refugees and address the root causes of problem.
Despite decades of persecution, the Rohingya in Myanmar's western Rakhine state largely eschewed violence.
But in October ARSA, a small and previously unknown militant group, staged a series of well coordinated and deadly attacks on security forces.
Myanmar's military responded with a massive security crackdown. Some 87,000 new refugees flooded into Bangladesh bringing with them harrowing stories of murder, rape and burned villages.
The UN believes the army's response many amount to ethnic cleansing, allegations denied by the government of Aung San Suu Kyi and the army.
In recent months the day-to-day fighting died down, but civilians described being trapped between army "clearance operations" and an assassination campaign by the militants, who are murdering anyone suspected of collaboration.